JP4448684B2 - Method for producing acyloxybenzenesulfonic acid or salt thereof - Google Patents

Description

  The present invention relates to a method for producing acyloxybenzene sulfonic acid or a salt thereof, and more particularly, to a method for industrially advantageously producing acyloxybenzene sulfonic acid or a salt thereof that has a good hue and has no odor problems.

Acyloxybenzene sulfonate generates organic peracid easily even at low temperatures by contacting it with hydrogen peroxide generating substrate represented by sodium percarbonate and sodium perborate and hydrogen peroxide in water. It is a particularly useful compound as a bleach activator because it exhibits an effective bleaching performance against dirt, stains and the like (see, for example, Patent Document 1).
As a method for producing an acyloxybenzene sulfonate, a method of reacting a phenol sulfonate with a carboxylic acid anhydride using a sulfonic acid as a catalyst in a polar neutral solvent is known (for example, see Patent Document 2). Yes. In this method, since a large amount of carboxylic acid having an equimolar amount or more with respect to the added carboxylic acid anhydride is by-produced, there is a problem that a burden in the purification process is large.
In addition, a method of reacting in the presence of a carboxylic acid when producing an acyloxybenzene sulfonate by reacting a phenol sulfonate and a carboxylic acid chloride (for example, see Patent Document 3) is known. In this method, since equimolar hydrogen chloride is by-produced with respect to the added carboxylic acid chloride, a facility capable of withstanding corrosive hydrogen chloride is required, which is disadvantageous in construction of the apparatus.

In addition, a method of reacting phenol sulfonate, acetic anhydride and carboxylic acid while simultaneously distilling off by-product acetic acid, and washing and isolating acyloxybenzene sulfonate with a hydrophilic solvent after completion of the reaction (for example, patent document) 4) is also known. However, Patent Document 4 does not sufficiently study the conditions for acetic acid distillation.
Further, a method in which a phenol sulfonate and acetic anhydride are reacted to form an acetoxybenzene sulfonate, then a carboxylic acid having a desired alkyl chain is added, and a transesterification reaction is performed while distilling off the by-produced acetic acid. (For example, see Patent Document 5) is also known. However, in Patent Document 5, since the transesterification reaction is performed at a high temperature of 190 to 240 ° C. under normal pressure, the resulting acyloxybenzene sulfonate is strongly colored and has a sharp odor, which is not satisfactory in practice.

JP 59-22999 A JP-A-60-202856 JP-A-8-53405 JP-A-2-73053 Japanese Patent Publication No. 4-1739

  An object of the present invention is to provide a method for industrially advantageously producing acyloxybenzene sulfonic acid or a salt thereof having a good hue and no odor problem under such circumstances.

As a result of studying the coloring and odor removal of acyloxybenzene sulfonate, the present inventors have removed low-boiling components such as lower carboxylic acid by-produced during the formation reaction of acyloxybenzene sulfonate under specific conditions. It was found that the above-mentioned purpose can be achieved by carrying out the reaction.
That is, the present invention
(1) General formula (1)

Wherein R ¹ is a linear or branched alkyl or alkenyl group having 1 to 18 carbon atoms, M is a hydrogen atom or a cationic group, a is a valence of M, and n is an integer of 0 to 2. And when n is 2, two R ¹ may be the same or different.)
And a hydroxybenzenesulfonic acid represented by the general formula (2)
^{R 2 CO-O-COR 2} (2)
(Wherein R ² represents a linear or branched alkyl group having 1 to 3 carbon atoms) and a general carboxylic acid anhydride represented by the general formula (3)
R ³ COOH (3)
(Wherein R ³ represents a linear or branched alkyl group or alkenyl group having 4 to 17 carbon atoms), and is reacted with a carboxylic acid represented by the general formula (4)

(Wherein R ¹ , R ³ , M, a and n are the same as described above.)
A process for producing an acyloxybenzenesulfonic acid or a salt thereof represented by:
Hydroxybenzenesulfonic acid represented by the general formula (1) or a salt thereof: a lower carboxylic acid anhydride represented by the general formula (2): a mixing ratio of the carboxylic acid represented by the general formula (3) ( Molar ratio) is in the range of 1: 0.9 to 2.4: 0.9 to 2 and at a temperature of 80 to 190 ° C. under reduced pressure, while distilling off low-boiling components produced in the reaction from the reaction system, A method for producing an acyloxybenzenesulfonic acid represented by the general formula (4) or a salt thereof , wherein the reaction is performed;
I will provide a.

  According to the production method of the present invention, by removing low-boiling components such as lower carboxylic acid produced as a by-product during the acyloxybenzene sulfonate formation reaction under specific conditions, there is a problem of good hue and odor. Acyloxybenzenesulfonic acid or a salt thereof can be advantageously produced industrially. For this reason, the obtained acyloxybenzenesulfonic acid or a salt thereof can be used as a bleaching activator or the like as it is without carrying out a treatment for removing colored substances and odorous substances by activated carbon or the like.

  In the production method of the present invention, as a raw material, the general formula (1)

Wherein R ¹ is a linear or branched alkyl or alkenyl group having 1 to 18 carbon atoms, M is a hydrogen atom or a cationic group, a is a valence of M, and n is an integer of 0 to 2. And when n is 2, two R ¹ may be the same or different.)
Or a salt thereof is used.
In the general formula (1), examples of the linear or branched alkyl group or alkenyl group having 1 to 18 carbon atoms represented by R ¹ include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group. , Isobutyl group, sec-butyl group, tert-butyl group, various pentyl groups, various hexyl groups, various octyl groups, various decyl groups, various dodecyl groups, various tetradecyl groups, various hexadecyl groups, various octadecyl groups, vinyl group, propenyl Groups, allyl groups, various octenyl groups, various decenyl groups, various dodecenyl groups, various hexadecenyl groups, oleyl groups, etc., among which methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group , A straight chain having 1 to 4 carbon atoms selected from sec-butyl group and tert-butyl group Ku is preferably a branched alkyl group. n is preferably 0 or 1, more preferably 0.

  The cationic group in M includes alkali metals such as sodium, potassium and lithium; alkaline earth metals such as calcium, barium and magnesium; ammonium; substituted ammonium such as diethanolammonium and triethanolammonium; tetramethylammonium And quaternary ammonium such as didecyldimethylammonium, but alkali metals are preferable, and sodium is particularly preferable from an industrial viewpoint.

The hydroxybenzene sulfonic acid or salt thereof used in the present invention contains 70% by mass or more, preferably 80% by mass or more of the para-form of general formula (1) in hydroxybenzene sulfonic acid or salt thereof. Also included are those in which an alkyl group or an alkenyl group is introduced onto the benzene ring as represented by the general formula (1).
In the present invention, the hydroxybenzenesulfonic acid represented by the general formula (1) or a salt thereof is represented by the general formula (5).

(In the formula, R ¹ and n are the same as described above.)
Can be obtained by sulfonating the phenol represented by the formula (1) or a derivative thereof to form hydroxybenzenesulfonic acid, and then adding an alkali as desired to form a salt of the sulfonic acid group or the sulfonic acid group and the hydroxyl group.
In the general formula (5), when n is 1 or 2, the introduction position of R ¹ with respect to the OH group may be other than the para position, and is not particularly limited.

  Sulfonation of the phenol represented by the general formula (5) or a derivative thereof can be performed using a conventionally known method. For example, phenol or a derivative thereof and concentrated sulfuric acid (concentration of about 98% by mass) slightly larger than the stoichiometric amount is heated at a temperature of about 50 to 150 ° C., preferably in an inert gas atmosphere such as nitrogen. Then, the corresponding hydroxybenzenesulfonic acid is obtained by sulfonation. In the present invention, the reaction conditions are selected so that the content of the para isomer in the hydroxybenzenesulfonic acid thus obtained is 70% by mass or more, preferably 80% by mass or more.

In the present invention, in the hydroxybenzenesulfonic acid thus obtained, a sulfonic acid group or a sulfonic acid group and a hydroxyl group are converted into a salt as desired. Examples of the salt include alkali metal salts, alkaline earth metal salts, ammonium salts, substituted ammonium salts, and quaternary ammonium salts, but alkali metal salts such as sodium salts and potassium salts are preferable, and sodium salts are particularly preferable.
There is no restriction | limiting in particular about the method of converting the sulfonic acid group in the said hydroxybenzenesulfonic acid or a sulfonic acid group, and a hydroxyl group into a salt, A conventionally well-known method can be used. Specifically, about 1 to 10 parts by weight of hydroxybenzene sulfonic acid, about 1 to 10 parts by weight of water and a substantially stoichiometric amount of an alkaline aqueous solution are, for example, about 40 to 100 ° C. The target salt can be obtained by contact treatment at temperature. The alkaline aqueous solution is preferably an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, and particularly preferably an aqueous sodium hydroxide solution. In the present invention, the substantially stoichiometric amount means an amount of about 0.95 to 1.05 times the stoichiometric amount.

In the present invention, the hydroxybenzenesulfonic acid represented by the general formula (1) or a salt thereof thus obtained, and the general formula (2)
^{R 2 CO-O-COR 2} (2)
(Wherein R ² represents a linear or branched alkyl group having 1 to 3 carbon atoms) and a general carboxylic acid anhydride represented by the general formula (3)
R ³ COOH (3)
(In the formula, R ³ represents a linear or branched alkyl group or alkenyl group having 4 to 17 carbon atoms.) By reacting with a carboxylic acid represented by the general formula (4)

(Wherein R ¹ , R ³ , M, a and n are the same as described above.)
The acyloxybenzenesulfonic acid represented by these or its salt is manufactured.
The acyloxybenzene sulfonic acid or salt thereof in the present invention contains 70% by mass or more, preferably 80% by mass or more of the para-form of general formula (4) in the acyloxybenzene sulfonic acid or salt thereof. Also included are those in which an alkyl group or an alkenyl group is introduced on the benzene ring as represented by the general formula (4).

The lower carboxylic acid anhydride represented by the general formula (2) is a carboxylic acid anhydride in which R ² has a linear or branched alkyl group having 1 to 3 carbon atoms. Among these, acetic anhydride and propionic anhydride are particularly preferable.
The carboxylic acid represented by the general formula (3) is a carboxylic acid having R ³ having a linear or branched alkyl group or alkenyl group having 4 to 17 carbon atoms. Among these, considering the performance when using the acyloxybenzenesulfonic acid represented by the general formula (4) or a salt thereof as a bleach activator, water-solubility, hard water resistance, and environmental load, A carboxylic acid having a linear or branched alkyl group having 7 to 13 carbon atoms is preferred. Specific examples of preferred carboxylic acids include caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, 2-ethylcaproic acid, 3,7-dimethylcaproic acid, 3,5,5-trimethylcaproic acid, 2- Examples include methyl caprylic acid and 2-methyl capric acid.

Next, the hydroxybenzenesulfonic acid represented by the general formula (1) or a salt thereof, the lower carboxylic acid anhydride represented by the general formula (2), and the carboxylic acid represented by the general formula (3). The reaction with an acid will be described.
In this reaction, it is preferable to use the hydroxybenzenesulfonic acid represented by the general formula (1) or a salt thereof in a substantially anhydrous state. Here, the term “substantially anhydrous” is not limited to a completely anhydrous state, but a small amount of water contained in the raw material itself, for example, a water amount of about 0.5% by mass or less is substantially anhydrous. If water exceeding about 0.5% by mass is present, the acylating agent may be hydrolyzed and the reaction yield may be reduced.
When dehydration treatment is performed to make the hydroxybenzenesulfonic acid or salt thereof substantially anhydrous, for example, the hydroxybenzenesulfonic acid or salt thereof is 0.01 to 200 ° C. at a temperature of about 110 to 200 ° C. Dry under reduced pressure of about ~ 60 kPa, or add about 0.05 to 20 parts by mass of an organic compound azeotropic with water such as benzene or toluene to 1 part by mass of the hydroxybenzenesulfonic acid or salt thereof. What is necessary is just to perform boiling dehydration. By such a dehydration process, a water content of about 0.5% by mass or less can be easily obtained.

  When the hydroxybenzenesulfonic acid represented by the general formula (1) or a salt thereof is introduced into the reaction vessel, it may be adjusted to a flake shape, a powder shape, a granular shape, etc., but dispersed in a solvent. The slurry is industrially simple and advantageous. Hydroxybenzene sulfonic acid or a salt thereof dispersed in a solvent and made into a slurry can be used by evaporating and distilling off the moisture, if necessary. As a solvent used here, a solvent having a boiling point higher than that of water is preferable, and it is particularly preferable to use a carboxylic acid represented by the general formula (3) as a reaction raw material.

  Next, the hydroxybenzenesulfonic acid represented by the general formula (1) or a salt thereof, the lower carboxylic acid anhydride represented by the general formula (2), and the carboxylic acid represented by the general formula (3). The acid is mixed and reacted. Although there is no restriction | limiting in particular about the mixing ratio (molar ratio) in that case, From the viewpoint of reaction selectivity and handling, those 3 mixing ratios (molar ratio) are 1: 0.5-2: 0.5- 5, particularly 1: 0.9 to 2: 0.9 to 5, more preferably 1: 0.9 to 1.5: 0.9 to 2.

In the production method of the present invention, the reaction temperature may be any temperature as long as the reaction raw material reacts and low boiling point components such as lower carboxylic acid by-produced during the reaction can be distilled off. If too much, the hue of the product may be deteriorated. Further, the acyloxybenzenesulfonic acid represented by the general formula (4) or a salt thereof, which is a reaction product, is a cleaning component and has a foaming property. Sudden foaming may be caused and it may be difficult to continue the reaction. For this reason, it is preferable to distill off low-boiling components such as by-product lower carboxylic acid as slowly as possible.
From the above viewpoint, in the production method of the present invention, the reaction is carried out while distilling off the low-boiling components in the middle of the reaction or immediately before the completion in the temperature range of 80 to 190 ° C. under reduced pressure. Preferably, the pressure in the reaction system is gradually decreased from normal pressure over 0.5 hours or more, the degree of vacuum is 0.1 to 54 kPa, particularly 0.1 to 13 kPa, and the reaction temperature is gradually increased over 1 hour or more. By raising the temperature to 80 to 190 ° C., particularly 100 to 180 ° C., and further 120 to 180 ° C., the low boiling point component can be distilled off continuously or stepwise.

  More specifically, for example, the reaction system is an inert gas atmosphere such as nitrogen, the temperature of the reaction system is first increased to 55 to 80 ° C., and the pressure is decreased from normal pressure to 20 to 40 kPa over 5 to 30 minutes, While maintaining the pressure, when the temperature is gradually raised to 100 to 130 ° C. over 0.5 to 2 hours, distillation of low boiling components begins. Next, while maintaining the temperature, the pressure in the system is gradually decreased to 0.5 to 5 kPa over 30 to 100 minutes, and maintained as it is for 0.5 to 2 hours, and then the temperature is gradually increased. 120 to 180 ° C., and the operation of maintaining the state as it is for 0.5 to 20 hours can be performed to distill off low-boiling fractions such as acetic acid and other lower carboxylic acids and unreacted products. .

In the production method of the present invention, the use of a catalyst is not essential, but the use of a catalyst may increase the reaction rate and lower the required reaction temperature. As the catalyst, a basic catalyst such as an alkali metal salt such as sodium acetate, an alkaline earth metal salt, or an acidic catalyst can be used.
Depending on the composition of the reaction raw materials, etc., the viscosity of the reaction system may be high. In this case, use a reactor equipped with a high-powered stirring device or a stirring blade for high-speed rotation such as a crescent moon type or squid type. be able to.
After completion of the reaction, the pressure of the reaction system is returned to normal pressure, the reaction product is cooled and filtered, and can be subjected to a recrystallization step or a washing step as necessary.
In the washing step, the reaction product is washed with a solvent to remove carboxylic acid and the like. Examples of the solvent that can be used here include alcohols such as methanol, ethanol, and propanol, aliphatic hydrocarbons such as hexane, aromatic hydrocarbons such as toluene and xylene, and ketones such as acetone. Moreover, carboxylic acid and a solvent can be collect | recovered from the washing | cleaning liquid after reaction product washing | cleaning by distillation etc., and can be reused as a raw material of this invention method.
After completion of the washing step, the resulting acyloxybenzenesulfonic acid or salt thereof contains a trace amount of solvent, which can be completely removed by heating under reduced pressure or the like.

The acyloxybenzenesulfonic acid represented by the general formula (4) or a salt thereof thus obtained removes low-boiling components such as a lower carboxylic acid by-produced during the production reaction under specific conditions. Therefore, it has higher purity than conventional ones, has a good hue, and has no odor problems. For example, when the reaction product containing acyloxybenzenesulfonic acid or its salt obtained in the above reaction is dissolved in a solution for evaluating hue, a solution having a concentration of 5% by mass is prepared, and the color of the solution is compared with the APHA standard solution. Normally, the APHA is 300 or more, but the APHA is 200 or less, preferably 150 or less.
Further, if the reaction product is filtered and washed, the purity of acyloxybenzenesulfonic acid or a salt thereof can be 80% by mass or more, preferably 85% by mass or more. The APHA of a 10 mass% solution of this acyloxybenzene sulfonic acid or salt thereof is 50 or less. Also, the odor is not problematic at all in practice.
Therefore, the acyloxybenzene sulfonic acid obtained by the present invention or a salt thereof may be subjected to a treatment for removing colored substances and odorous substances with activated carbon, if necessary. You can use it as it is.
This acyloxybenzenesulfonic acid or a salt thereof, particularly an alkali metal salt, can easily form an organic peracid at a low temperature by contacting with hydrogen peroxide generating substrate such as sodium percarbonate or sodium perborate or hydrogen peroxide in water. Since it generates and exhibits an effective bleaching performance against dirt such as clothes and stains, it can be used as a bleaching activator in a detergent composition or the like.

Example 1
In a 500 mL four-necked flask equipped with a stirrer equipped with a crescent stirring blade, a thermometer, a nitrogen blowing tube, a reflux condenser, and a distillate collection vessel, 155.8 g of sodium hydroxybenzenesulfonate (purity: 82.2%) Then, 261.8 g of lauric acid and 80.0 g of acetic anhydride were added (sodium hydroxybenzenesulfonate: lauric acid: acetic anhydride (molar ratio) = 1: 1.2: 2) , and nitrogen flow and stirring were started. Next, the temperature was raised to 60 ° C., the pressure in the system was lowered to 27 kPa over 10 minutes with a vacuum pump, and while maintaining the pressure, the temperature was gradually raised to 120 ° C. over 103 minutes. The outing has begun. Next, while maintaining the temperature, the pressure in the system was gradually lowered to 1.3 kPa over 60 minutes, and the state was maintained for 1 hour. Further, while maintaining the pressure, the temperature was gradually raised by heating to 170 ° C., and the state was maintained as it was for 1 hour, and low-boiling fractions such as acetic acid produced as a by-product were distilled off. Thereafter, while flowing nitrogen, the system pressure was returned to normal pressure, and the system was cooled to 50 ° C. The weight of the obtained reaction product was 372.4 g, and the content of sodium lauroylbenzenesulfonate was 57.8% by mass. The yield of sodium lauroylbenzene sulfonate was 87.1% in mole% of sodium hydroxybenzene sulfonate.
This reaction product is dissolved in a solution of isopropyl alcohol: water volume ratio = 2: 8 to form a solution having a sodium lauroyloxybenzenesulfonate concentration of 5% by mass, and the color of the solution is compared with the APHA standard solution to obtain a hue. As a result of evaluation, APHA120 was obtained. Moreover, the odor of this reaction product was practically satisfactory.

Next, 100 g of ion-exchanged water was added to the obtained reaction product, heated to 90 ° C., and maintained for 1 hour to obtain a transparent liquid. Next, it cooled to 30 degreeC over 90 minutes, and precipitated the product. The resulting precipitate was filtered off, and 100 g of ion-exchanged water was passed through the product on the filter. The product was dried at 80 ° C. and 13.3 kPa for 12 hours. The obtained dried product had a purity of 94.3% by mass of sodium lauroyloxybenzenesulfonate. The obtained dried product was dissolved in a solution of acetonitrile: water mass ratio = 1: 1 to prepare a solution having a sodium lauroyloxybenzenesulfonate concentration of 10% by mass, and the hue was evaluated. As a result, APHA20 was obtained. There was no problem with the odor of sodium lauroylbenzenesulfonate.

The reaction product was analyzed by liquid chromatography using the following column, eluent and detector.
<Quantification of sodium lauroyloxybenzenesulfonate>
Column: GL Science Inc. Inertsil ODS-3V (5 μm), 150 mm × 4.6 mmΦ
Eluent: water / methanol = 600 mL / 2400 mL containing tetrabutylammonium bromide 17.3 g, acetic acid 5 mL Detector: RI

Example 2
In a 500 mL Separa flask equipped with a stirrer equipped with a squid type stirring blade, a thermometer, a nitrogen blowing tube, a reflux condenser, and a distillate collection container, 49.4 g of sodium hydroxybenzenesulfonate (purity 82.2%), 50.4 g of lauric acid and 51.6 g of acetic anhydride were added (sodium hydroxybenzenesulfonate: lauric acid: acetic anhydride (molar ratio) = 1: 2.4: 1.2) , and nitrogen flow and stirring were started. The Separa flask was immersed in an oil bath, the temperature inside the system was raised to 75 ° C., and the pressure was reduced to 27 kPa over 10 minutes with a vacuum pump. While maintaining the pressure, the temperature was gradually raised by heating, and when the temperature was raised to 120 ° C. over 86 minutes, distillation of the low boiling point component began. Next, while maintaining the temperature, the pressure in the system was gradually lowered to 1.3 kPa over 60 minutes, and the state was maintained for 1 hour. Further, while maintaining the pressure, the temperature was gradually raised by heating to 170 ° C., and the state was maintained as it was for 20 hours to distill off low-boiling fractions such as acetic acid produced as a by-product. Thereafter, while flowing nitrogen, the system pressure was returned to normal pressure, and the system was cooled to 50 ° C. The weight of the obtained reaction product was 108.3 g, and the content of sodium lauroylbenzenesulfonate was 76.4% by mass. The yield of sodium lauroylbenzenesulfonate was 90.3% in terms of mole% of sodium hydroxybenzenesulfonate.
As a result of evaluating the hue of this reaction product in the same manner as in Example 1, it was APHA90. Moreover, the odor of this reaction product was practically satisfactory.
Next, 100 g of ion-exchanged water was added to the obtained reaction product, heated to 90 ° C., and maintained for 1 hour to obtain a transparent liquid. Next, it cooled to 30 degreeC over 90 minutes, and precipitated the product. The resulting precipitate was filtered off, and 100 g of ion-exchanged water was passed through the product on the filter. The product was dried at 80 ° C. and 13.3 kPa for 12 hours. The purity of the obtained sodium lauroyloxybenzenesulfonate was 94.3% by mass, APHA evaluated in the same manner as in Example 1 was 20, and there was no problem with odor.

Example 3
The same 500 mL four-necked flask used in Example 1 was charged with 287.4 g of a 30% aqueous sodium hydroxybenzenesulfonate solution, and nitrogen flow and stirring were started. Next, the temperature was raised to 100 to 110 ° C. under normal pressure, and the state was maintained for 3 hours to distill 132.1 g of water. Next, 174.4 g of lauric acid was charged, and the pressure in the system was gradually lowered to 1.3 kPa with a vacuum pump. While maintaining the pressure, the temperature was gradually raised to 170 ° C. over 60 minutes, and the state was maintained for 3 hours. Thereafter, while flowing nitrogen, the system pressure was returned to normal pressure, the system was cooled to 50 ° C., and a slurry was collected. The obtained mixed slurry of sodium dehydrated hydroxybenzenesulfonate and lauric acid was 293.5 g. The water content of the collected slurry was measured by the Karl Fischer method and found to be 0.01%.
290 g of this mixed slurry of sodium hydroxybenzenesulfonate and lauric acid (containing 85.2 g of sodium hydroxybenzenesulfonate) and 53.2 g of acetic anhydride were charged into the same 500 mL four-necked flask used in Example 1. (Sodium hydroxybenzenesulfonate: lauric acid: acetic anhydride (molar ratio) = 1: 1.2: 2) , nitrogen flow and stirring were started. Next, the temperature was raised to 60 ° C., and the pressure in the system was lowered to 27 kPa over 10 minutes with a vacuum pump. While maintaining the pressure, the temperature was gradually raised to 120 ° C. over 95 minutes by heating, and distillation of the low boiling point component started. Next, while maintaining the temperature, the pressure in the system was gradually lowered to 1.3 kPa over 60 minutes, and the state was maintained for 1 hour. Further, while maintaining the pressure, the temperature was gradually raised to 170 ° C., and the state was maintained for 1 hour, and low-boiling fractions such as acetic acid produced as a by-product were distilled off. Thereafter, while flowing nitrogen, the system pressure was returned to normal pressure, and the system was cooled to 50 ° C. Thereafter, while flowing nitrogen, the system pressure was returned to normal pressure, and the system was cooled to 50 ° C. The weight of the obtained reaction product was 259.0 g, and the content of sodium lauroylbenzenesulfonate was 52.1%. The yield of sodium lauroylbenzenesulfonate was 82.0% in mole% of sodium hydroxybenzenesulfonate.
As a result of evaluating the hue of this reaction product in the same manner as in Example 1, it was APHA100. Moreover, the odor of this reaction product was practically satisfactory.

Comparative Example 1
The same 500 mL four-necked flask used in Example 1 was charged with 122.7 g of sodium hydroxybenzenesulfonate (purity 82.2%), 59.8 g of lauric acid, and 37.5 g of acetic anhydride, and the system was filled with nitrogen. The nitrogen flow and stirring were started. Next, it heated up to 155 degreeC over 30 minutes by heating, and was hold | maintained as it was for 40 minutes. Next, the temperature was further raised to 175 ° C., and the state was maintained for 315 minutes. At this time, the sample was collected and analyzed, and as a result, the content of sodium lauroylbenzenesulfonate was 30.0%.
The system was further heated to a temperature of 230 ° C. and held for 1 hour in the state as it was. After distilling off low-boiling fractions such as acetic acid as a by-product, the system was cooled. The weight of the obtained reaction product was 155.8 g, and the content of sodium lauroylbenzenesulfonate was 43.3%. The yield of sodium lauroylbenzenesulfonate was 71.2% in mole percent of sodium hydroxybenzenesulfonate.
As a result of evaluating the hue of this reaction product in the same manner as in Example 1, it was APHA400. The reaction product also had a sharp odor.

The acyloxybenzenesulfonic acid or salt thereof obtained by the production method of the present invention has a good hue and no odor problems, and is used as a bleaching activator in a cleaning composition.

Claims (7)

General formula (1)

Wherein R ¹ is a linear or branched alkyl or alkenyl group having 1 to 18 carbon atoms, M is a hydrogen atom or a cationic group, a is a valence of M, and n is an integer of 0 to 2. And when n is 2, two R ¹ may be the same or different.)
And a hydroxybenzenesulfonic acid represented by the general formula (2)
^{R 2 CO-O-COR 2} (2)
(Wherein R ² represents a linear or branched alkyl group having 1 to 3 carbon atoms) and a general carboxylic acid anhydride represented by the general formula (3)
R ³ COOH (3)
(Wherein R ³ represents a linear or branched alkyl group or alkenyl group having 4 to 17 carbon atoms), and is reacted with a carboxylic acid represented by the general formula (4)

(Wherein R ¹ , R ³ , M, a and n are the same as described above.)
A process for producing an acyloxybenzenesulfonic acid or a salt thereof represented by:
Hydroxybenzenesulfonic acid represented by the general formula (1) or a salt thereof: a lower carboxylic acid anhydride represented by the general formula (2): a mixing ratio of the carboxylic acid represented by the general formula (3) ( Molar ratio) is in the range of 1: 0.9 to 2.4: 0.9 to 2 and at a temperature of 80 to 190 ° C. under reduced pressure, while distilling off low-boiling components produced in the reaction from the reaction system, A method for producing an acyloxybenzenesulfonic acid represented by the general formula (4) or a salt thereof, which causes the reaction.   The process for producing acyloxybenzenesulfonic acid or a salt thereof according to claim 1, wherein low-boiling components are gradually distilled off from the reaction system under a reduced pressure of 0.1 to 54 kPa in the middle of or just before completion of the reaction.   The acyloxybenzenesulfonic acid or a salt thereof according to claim 1 or 2, wherein the low-boiling components are distilled off from the reaction system by reducing the reaction system from normal pressure to 0.1-54 kPa over 0.5 hours or more. Manufacturing method.   The method for producing acyloxybenzenesulfonic acid or a salt thereof according to claim 1 or 2, wherein the low boiling point component is distilled off from the reaction system by heating the reaction system to 120 to 180 ° C over 1 hour or more.   The method for producing acyloxybenzenesulfonic acid or a salt thereof according to any one of claims 1 to 4, wherein the lower carboxylic acid anhydride is acetic anhydride.   The acyloxybenzenesulfonic acid or salt thereof according to any one of claims 1 to 5, wherein the APHA of the 5 mass% solution of the reaction product containing the acyloxybenzenesulfonic acid or salt thereof obtained by the method is 200 or less. Manufacturing method.   The method for producing an acyloxybenzenesulfonic acid or a salt thereof according to any one of claims 1 to 6, wherein the APHA of the acyloxybenzenesulfonic acid or a salt thereof having a concentration of 10% by mass obtained by the method is 50 or less.